"I've kept fish for going on 40 years" just a beginner; I have over 45 years....lol.
Over-filtration has the potential to actually increase waste in the system.
There was a good thread a couple years ago addressing waste removal and the number of canister filters. If you have a tank with two canisters, you may rotate cleaning every month, so one filter gets cleaned every two months (effectively removing x% of the solid waste trapped inside. If you had 5 canisters on the same tank, you have to clean one canister in less than 30 days to effectively match the waste decomposition of only having two canisters.
Someone can do the math, but the issue is if you don't increase your filter cleaning effort (i.e., more than 5 filter cleanings in a 5 month period) the waste sits in each of the 5 canisters longer and more of the solid waste gets broken down and released back into the tank.
Because I have so much else going on in my life, I try to keep my fish care cleaning time to a minimum. For example, I only have two AC110s on my 125G tank (HOBs take less time to clean than canisters). Each filter gets cleaned once a month.
The other "secret" is paying attention to the water you use for WCs.
Each time I moved in the past, my water was different. From living at home (well water that was soft and acidic) to now where the water is very alkaline, hard, loaded with heavy minerals, has chloramine, and changes in quality (bad to worse) during the year.